Clamp for stretching leather and the like



Oct. 30,1923. 1,472,617

J. M. SCHWARTZ CLAMP FOR STRETCHING LEATHER AND THE LIKE Filed June 8. 1922 INVENTOR BY Z ATTORNEVJ Patented Get. 39, 1923.

JAB/ ES llI. SCH'WAB-TZ, BOONTON, NEW JERSEY, ASSIGNOR T0 SCHWARTZ BELTING 00., A CGRPQRA'IIQN OF NEW YORK. 7

ensure non s'rnnronrns LEATHER AND THE LiKE.

Application filed June 8,

To all whom it may concern:

Be it known that I, JAiJns M, Sonwixnrz, a citizen of the United States, and a resident of Boonton, in the county of Morris and State of New Jersey, have invented new and useful Improvements in Clamps for Stretching Leather and the like, of which the following is a specification.

This invention relates more especially to clamps used to engage the ends ofthe pieces of leather known as butt bends which are utilized for the manufacture of belting, said clamps being used to hold one end of such butt bend while it is being stretched as is common in the art, although it will be understood that some features of the invention may be used upon any clamp to which they are applicable.

The objects of the invention are to utilize in a machine 'of the character set forth quick clamping and releasing means for holding the leather while being stretched, and thus greatly increase the capacity or output of the machine without detracting from a secure holding of the leather or in any other respect lessening the efficiency of the machine; to provide in combination a support and clamping jaws anda quickacting member for simultaneously clamping material in said jaws and said jaws to said support; to enable such a quick clamping and releasing means to be adjusted to accommodate various thicknesses of leather, and further to provide such adjusting means as will hold the quick clamping and releasing member in spaced position for the insertion of the leather; to provide such spacing means to connect the quick clamping and.releasing member to the support at the opposite side ofthe leather, and furthermore to utilize said spacing means as a guideway for said member; to adjustably position such a quick clamping and releasing member with respect to a clamping jaw of a clamp by means of a bolt having a nut carrying said quick clamping and. releasing member, and to obtain other advantages and results as may be brought out by the following description. v

Referring to the accompanying drawings, in which like numerals of reference indicate the same parts throughout the several views,

Figure l is a plan of a portion of an end 1922; Serial No. 566,786.

plate of a leather stretching machine, showing thereon a portion of a butt bend with some of my improved clamps engaging the same Figure 2 1s ing is to be formed, a portion of one of which is indicated by the reference numeral 1 in said drawings, is stretched in a suitable machine, its straight end being held by clamping jaws, not shown, and its other a vertical sectional view i through one of the slots and leather, showend, which is irregular in outline as at 2,

being held by a plurality of separate clamps each ofwhich is adjustable longitudinally of the piece of leather in a slot 3 in a plate or support which is usually fixed on the machine as a stretcher-head, so that said clamps can be moved into position to properly engage the saidirregular end edge 2 of the leather.

Each of said clamps, as shown in detail in Figures 2 and 3, comprises a bolt 5, projecting up through one. of the slots 3 in the plate 4, said bolt having at its lower end beneath said plate ahead 6 and above said plate passing through cooperating jaws -7,

8, which are adapted to grip the margin of theqleather l with great force. I have shown the lower jawS as serrated at its under surface so as to not slip on the plate A} and provided at therear of the bolt 5 with a recess 9 to receive a fulcrumal proj ection 10 on the upper jaw, while at the opposite ends the lower jaw has grooves ll and the upperjaw has a block '12 of wood, copper or other relatively soft material, to force the leather into said grooves 11. Dowel pins 13 fast on the lower jaw 8 near its rear fulcrumal edge extend loosely lnto holes 14 in the upper jaw 7 to retain the.

jaws in position relative to each other.

It will be understood that the detail construction of these jaws is not material to my invention, and might be changed with out departing therefrom.

My invention relates more especially to the quick clamping and releasing member upon the upper end of the bolt 5 for forcing the jaws 7, 8 together to grip the leather, and in the particular embodiment of it shown in the drawings 15 is a nut threaded upon the upper end of the bolt 5 and pro vided at opposite lateral sides of itself with trunnions 16, 16 which receive each a cam 17, said cams having arms 18, 18, between which a filler block 10 is placed and secured by rivets 20 or the like extending through said filler block and arms, Preferably the filler block 10 is provided with an end projection 21 to receive an operating handle 22 which is removable to permit its application to various clamps in succession.

In operation it will be understood that the workman having adjusted the clamp to its proper position so that its jaws 7 8 receive between themselves the edge of the leather 1 with the cams 17 in released position, as shown by dotted lines in Figure 2, simply throws down the handle 22 so as to bring the cams 17 into engagement with the upper jaw 7 and force it into clamped relation to the leather, as shown in full lines in Figure 2 and at the same time clamp the jaws against movement on the support 4. This can be done very quickly and forcibly, so that a great deal of time, labor and expense is saved. If it should happen that the particular piece of leather to be clamped is thinner or thicker than the piece last clamped, so that the jaws 7, 8 are not the proper distance apart, the operator can instantly adjust for this by turning the nut 15 in one direction or the other, and he does this by the same lover or handle 22 by which he tightens the cams. This is a feature of my invention, that both the longitudinal adjustment of the nut 15 upon the bolt 5 and the tightening and loosening of the cams 17 with respect to the jaws 7, 8, is accomplished by the same handle or operating means. In doing this it is preferable to have the bolt 5 held against turning by some suitable means, such as squaring its shank next to the head 6, as at 50, to slidably fit the slot 3, see Figuie 3.

It will be understood that many variations of detail construction from the one shown in the drawings can be made without departing from the invention, and I do not wish to be understood as limiting myself except as set forth in the following claims when construed in the light of the prior art.

Having thus described the invention, what 'I claim is 1. In a stretching machine, the combina tion with a support, of clamping jaws to receive a piece of material to be stretched,

and a quick clamping and releasing member cooperating with said jaws to simultaneously clamp a piece of material in said jaws and said jaws against movement on said support.

2. In a stretching machine, the combination with a support, of clamping aws to receive a piece of material to be stretched, a bolt mounted on said support and passing through said jaws, a nut on said bolt, and a quick clamping and releasing member on said nut for simultaneously clamping a piece of leather in said jaws and said jaws against movement on said support.

3. In a stretching machine, the combination with a support, of clamping jaws to receive a piece of material to be stretched, a quick clamping and releasing member cooperating with said jaws to simultaneously clamp a piece of material in said jaws and said jaws against movement on said support. and an adjustable connection between said clamping and releasing member and said support for varying the opening between said jaws to accommodate material of different thicknesses.

4. In a stretching machine, the'combination with a support having an opening therethrough, a bolt loosely mounted in said opening and having a head larger than said opening arranged at one side of said support, jaws mounted on said support to receive a piece of material to be stretched, and a quick clamping and releasing member mounted on said bolt at the other side of said support to simultaneously clamp a piece of material in said jaws and said jaws against movement on said support.

5. In a stretching machine, the combination with a support having an opening therethrough, a bolt loosely mounted in said opening and having a head larger than said opening arranged at one side of said sup port, jaws mounted on said support to receive a piece of material to be stretched, a nut threaded on said bolt at the side of said support opposite said head, and a cam pivoted on said nut to simultaneously clamp a piece of material in said jaws and said jaws against movement on said support.

6. In a stretching machine, the combination with a support having an opening therethrough, a bolt loosely mounted in said opening and having a head larger than said 0 )enin arran ed at one side of said supsupport.

JAMES M. SCHWARTZ. 

